Temperature-control means for refrigerators



H. G. BUTZOW 1,768,886

TEMPERATURE CONTROL MEANS FOR REFRIGERATORS July 1 Filed May 29, 1929 4 JZ/Z/f aw,

Patented July 1, 1 930 UNITED STATES PATENT; OFFICE HENRY G. BUTZOW, OF SYCAMORE, ILLINOIS TEMPERATURE-CONTROL MEANS FOR REFRIGERATOR Application filed May 29,

. sive to the variations of pressure in the system and usually employs a sylphon bellows which, when artially collapsed, operates to open the switch against the action of a spring, thereby breaking the circuit to the motor and stopping the compressor. In accordance with the present invention, regulatable control means have been provided for regulating the tension of the spring to thereby vary the pressure at which the switch will operate, and, as a consequence,

cause the electric motor to operate for a longer or shorter period of time, as the case may be, thereby prolonging or retarding the action of the compressor. It is understood that the longer the compressor runs, the

lower the temperature is maintained.

The invention consists in the several novel features hereinafter fully set forth and claimed.

The invention is clearly illustrated in the drawing accompanying this specification in which- Figure 1 is a side elevation of a pressure switch equipped with control means embodying a simple form of the present invention;

I Fig. 2 is a detail vertical cross section taken on the line 2- 2 of Fig. 1;

Fig. 3 is a plan of the device detached 0 from the pressure switch; and

Fig. 4 is a side elevation of .a' slightly modified form of the invention.

Referring to said drawing, and first to Figs. 1 to 3, inclusive, the' reference character 5 designates the base of a pressure switch which is usually provided with legs 6 attached to any suitable support. The electric switch mechanism is seen at 7 and may be of any conventional form for closing the elecso tric circuit through conductors 8 that lead 1929. Serial No. 367,105.

to the motor (not shown) of the compressor of a refrigerating machine.

Ordinarily, a switch lever 9 is employed for operating the electric switch, and said lever receives its motion in a downward direction from a sylphon bellows 10 mounted upon the base 5 and having its upper wall connected to the switch lever 9. The sylphon bellows is usually contained within a cage 11- which protects the sylphon bellows against injury. A tube 12 leads from the interior of the sylphon bellows to the intake side of the compressor (not shown), and establishes communication therewith. The sylphon bellows is responsive to variations of the pressure produced.

The switch lever 9 is spring pressed in an upward direction by a coiled compression spring 13 which surrounds a tension rod 14 that is connected to the switch lever 9. The upper end of the spring 13 bears against a nut 15 threadedly secured upon the rod 14 for adjustment thereon. The u ward pressure of the spring 13 on the switc lever 9 operates to counteract downward movement thereof caused by the partial collapse of the sylphon bellows 10 resulting from a reduct1on of pressure therein below a predetermined point. A coiled compensating spring 16 surrounds the rod 14 and is interpcsed'between the lower side of the base 5 and a nut 17 threaded on the lower end of the rod.

The parts thus far described are common and well known and comprise the pressure switch of the well known Frigidaire refrigerator.

The base 5 is preferably formed of sheet metal having down turned side flanges 5", and the device forming the subject matter of this specification is arranged to be readily attached to said base. As shown in Fig. 2, the control device comprises a supporting or bracket member 18, a tension regulating lever 19 and an adjustment stud 20 threadedTy mounted in the bracket member 18 and adapted, when rotated therein, to rock the lever 19 and thereby apply more or less tension to the spring 13 of t e pressure switch.

The bracket member, 18 is preferably formed ofstrip metal having a straight horizontal portion 21 formed with an aperture 22 through which the rod 14 and spring 16 extend, and at one end said straight portion 21 is formed with a downwardly bent end portion 23 which bears against the inner side of one of the flanges 5. The other end of said straight portion is bent down and up to form a hook-like member 24 that engages over the other side flange 5 of the base.

The tension regulating lever 19 is formed with a horizontal straight arm 25 which extends above the base 5 and is forked at one end, as at 26, so as to straddle the rod 14. with the compression spring 13 bearing upon the upper side of the forked portion. Intermediate its ends the lever 19 is bent downward to form an arm 27 whichbears against the outer face of one of the side flanges 5 of the base. The lever fulcrums upon the upper side edge of the base, as at 28, and in the operation of the control device is rocked upon said fulcrum to regulate the tension of the spring 13.

Secured to the outer face of the arm 27 of the lever 19, or formed as a part thereof, is a dial plate 29 having suitable characters, such as numerals for indicating higher and lower temperatures, said dial plate being secured to said arm by screws or rivets 30, as shown. Upon the outer end of the adjustment stud 20 is a knob or handle 31 by means of which it may be manipulated, and a pointer 32 is provided upon said knob which co-operates with the characters on the dial to indicate higher and lower temperatures.

If desired, the adjustment stud may be formed separately from the knob or handle 31 and may be threadedly secured therein and locked thereon by a lock nut 33, which lock nut forms a shoulder that bears against the arm 27 of the lever 19 or against the outer face of the dial plate 29. It will be observed that by turning the adjustment screw in a clockwise direction, the arm 27 of the lever will be swung upon the fulcrum 28 towards the part 23 of the bracket member 18, and, as a consequence, the arm 25 of the lever will be swung upward, thereby increasing the tension of the spring 13. Conversely, if the adjustment stud is turned in a contra-clockwise direction, the arm 25 of the lever swings downwardly, thereby decreasing the tension of the spring 13.

From the above it will be understood that by swinging the arm 25 of the lever in an upward direction, the tension of the spring upon the switch lever 9 is increased, thereby requiring a lower pressure in the sylphon bellows to overcome the action of the spring 13 and open the switch, than when the ten sion of the spring is reduced. By swinging the arm 25 of the tension regulating lever in a downward direction, the tension of the spring 13 is reduced, thereby making it possible for a higher pressure to collapse the sylphon bellows and move down the switch lever 9 to open the switch. The length of time that the compressor remains in operation may thus be governed by the control device, and the temperature in the cooling chambers of the refrigerator may be regulated.

In the modified form of the invention illustrated in Fig. 4, remote control means have been provided for manipulating the adjustment stud 20 of the control device. In some installations, the pressure switch, motor compressor and other associated elements of the mechanism are placed in a basement, or at a place distant from the refrigerator itself.

To enable a person to operate the temperature control device from a remote point, I provide a drum 31 on the adjustment stud 2O instead of the knob or handle 31. Over the drum is wrapped a wire 31", to one end of which is attached a tension spring 31 fastened to any suitable support, and the other end of the wire leads through a tube 31 to a. drum 31 located at any suitable point above or beyond the control device. The drum 31 is provided with a handle 31 whereby it may be manipulated, and said drum may also be formed with a pointer 31 eo-operating with notches 31 in a dial plate 31 to hold the drum 31 in any place of adjustment. In this case also, the adjustment stud 20 is threadedly mounted in a bracket member and engages with a tension regulating lever, as in the preferred form, and by rotating the drum 31, the tension upon the spring 13 may be regulated, as has been above described in connection with the preferred form of the invention. The pressure switch may, of course, be arranged to operate in response to variations of pressure above or below atmospheric pressure, and wherever the term higher or lower pressure is mentioned in this specification, it refers to relative pressures above or below atmospheric pressure.

I claim as new and desire to secure by Let ters Patent:

1. A temperature control device for refrigerators comprising in combination a pressure switch of the sylphon bellows type and having a lever actuating compression spring, a tension regulating lever engaging with said compression spring and an adjustment stud having a shoulder bearing against said lever and acting to rock said lever upon its fulcrum when the adjustment stud is adjusted in the supporting member.

2. A temperature control device comprislng in combination a pressure switch of the sylphon bellows type and having a base and a spring pressed switch actuating lever, a substantially L-shaped supporting member having means for attachment with the base of the switch, a substantially L-shaped tension regulating lever fulcrumed on the base and having one arm engaging with the spring of the switch, and an adjustment stud f rotatably mounted in the down turned arm of threaded in said supporting member and having a shoulder bearing against said adjustment lever, said adjustment stud being adapted to rock said lever u on its fulcrum when adjusted in the supportin member.

3. A temperature control device for refrigerators comprising a substantially L-shaped supporting member having means for attachment with the base of an electric pressure. switch, a substantially L-shaped tension regulating lever having one arm arranged to engage the tension spring of the pressure switch and an arm extending right angles to the first mentioned arm, said lever being fulcrumed at the angle between the two arms, and an adjustment stud threadedly mounted in said supporting member and having a shoulder bearing against the down turned arm of the tension regulatin lever and adapted to rock the same upon lts fulcrum when the adjustment stud is adjusted in the supporting member.

4. A temperature control device for refrigerators comprising a substantially L- shaped supporting member havin means for attachment with the base of an e ectric pressure switch, a'substantially L-shaped tension regulating lever having one arm arranged to engage-the tension spring of the pressure switch and an arm extending at right angles to said first mentioned arm, said lever being fulcrumed at the angle between its arms, a

dial platecarried b saidlever, and an adjustment-stud rotata 1y mounted in said lever and threadedly secured in said supporting downward at the arms of the lever u on said base of the ranged to engage said lever.

HENRY G. BUTZOW.

member, said adjustment stud having a pointer co-operating with the dial, and a shoulder bearing against said dial late.

5. A temperature control device or refrigerators comprising a substantially L-shaped supporting member having means for attachment with the base of an electric pressure switch, a substantially L-shaped tension regulating lever arranged to engage the tension spring of the pressure switch said lever having a down turned arm extending at right angles to the first mentioned arm and the lever being fulcrumed at the angle between the arms upon the base of the pressure switch, a dial plate upon said lever, and an adjustment stud said lever and threadedly engaged in thesupporting member, said adjustment stud having a knob provided with a shoulder abutting against said dial plate.

6. A temperature control device for refrigerators comprising a substantially L-shaped supporting member formed with a hook at one end arranged to extend over the base of a pressure switch and formed with an aperture to receive a tension rod of the pressure switch, an L-shaped tension regulating lever substantially paralleling said supporting member and fulcrumed at the angle between 

